Perforating casing



N. A. NELSON PERFORATING CASING Filed Oct. 16, 1958 FIG. 3.

FIG. 4-

INVENTOR.

NOR MAN A.' N ELSON FIG.

ATTO

May 1, 1962 United States Patent 3,031,965 PERFORATING CASING Norman A. Nelson, South Houston, Tex., assignor, by

mesne assignments, to Jersey Production Research Company, Tulsa, Ghia., a corporation of Delaware Filed Oct. 16, 1958, Ser. No. 767,602 2 Claims. (Cl. 102-21.8)

The present invention is directed to apparatus for perforating a casing. More particularly, the invention 1s concerned with apparatus for perforating a casing having first and second parallel eccentrically arranged pipes there'- in. In its more specific aspects, the invention is concerned with perforating a casing having a pipe string arranged therein without perforating said pipe string.

The presen-t invention may be briefly described as apparatus for perforating a leasing having atleast first and second parallel eccentrically arranged pipes therein with the -rst ofthe pipes extending through a zone to be perforated, the apparatus comprising an elongated body adapted to be lowered into said zone through a second of the pipes to a position adjacent the first of the pipes. The elongated body is provided with perforating means carried thereby and is also provided with biasing means which are carried in a recess formed on the body. The biasing means serve to orient the body and the perforating means away from the irst pipe such that on 'operating the perforating means, the casing is perforated withoutperforating the rst pipe. The first pipe and the biasingrneans.cooperatively engageto orient the elongated body'for perforatng the casing with the perforating means. j j

The perforating means is suitably a bullet gun or may be a plurality of bullet guns. Likewise, the perforating means may be a shaped chargeor a plurality of shaped charges. Other perforating means such as mechanical or chemically operated perfora-ting means may be used. It is preferred, however, to provide as perforating meansa plurality of shapedcharges. f- A The biasing means may be a single or a plurality of spring members carried by said body member in recesses formed therein. The spring members are preferably carried by the body member to describe or enclose an angle no greater than 90 such that on cooperatively engaging with the first pipe the body member is oriented to position the perforating means for perforating the casing without perforating the iirst pipe. y

The iirst pipe may suitably carry a race longitudinally thereon yand the biasing means may suitably include spring biased race followerjmeans which cooperate with the race to orient and position the perforating means for perforating the casing without perforating the first pipe.

The first pipe may suitably extend through the zone to be perforated while the second pipe may terminate above the zone. Likewise, the rst pipe may terminate above a zone to be perforated with the second pipe being attached -to the first pipe adjacent its lower end and communicating fluidly therewith and extending through said zone such that on operating the perfor-ating means, only the casing is perforated.

The present inventionv also contemplates that engagement of the spring biased means with the first pipe or the race will cause the perforating means to be operated such as by completing an electrical circuit.

' The present invention will be further illustrated by reference to the drawing illustrating preferred embodiments in which: u

FIG. l shows a perforator being lowered into an upper zone for perforating same;

FIG. 2 is a sectional view taken along the lines 2--2 of FIG. 1;

3,031,965 Patented May l, '1962vr ice penetrated by vthe Well bore 12,. the lower end 17 ofv the tubing 14 being open and being positioned for production fromthe zone 16. A second tubing string 18 is arranged in the casing 11 with its lower open end 19 positioned in the upper zone 15 for production therefrom.v vIt will be notedthat the tubing 14 and l18, respectively, are positioned in vor above the upper or lowerl zones`which, incidentally, may be a plurality of hydrocarbon zones, respectively, for recompletion in said zones in accordance with the permanent well completion technique which has been described amply in the patent literature.

lt is to benoted that the upper zone is separated from the lower zone by a suitable packer 20 while the casingtubing -annulus 21 is closed by an upper packer 22.

A slotted guide sleeve 9 is provided in the lower end of tubing 18. Dependently connected to thellower end of tubing 18 and carried longitudinally Iby the tubing 14 by means of clamps vis a race member 23l for engagement by race followers 24 carried by an elongated body `25 provided with perforating meansV 26. 'I'he race member 23 has an operativeY curved surface 23a facing away from the tubing 14 and ytoward casing 11. Shoulders 23b prevent race follower 24 from slipping out of the race member 23. Body 25 is lowerable through tubing 18 by a conductor cable 27.

Body 25 is provided with an outwardly projecting vertically extending guide lug 10 which engages with the slotted guide sleeve 9 in tubing 18 to orient the angular position Vof body 25 las itA passes through the bottom of tubing 18. It will be noted that the guide .lug 10 extends abovel and below the race followers 24 whichare in the form of leaf springs. e

j While the body 25 is being lowered through the tubing 13 the race followers are held depressed within recesses 28 in body 25 by the wall of the tubing. The guide lug 10 contacting the guide sleeve 9 positions the body 25 so that when the section of body 25, housing the race followers, pa'sses out the bottomof tubing 18 the race followers are in a position to snap out and engage the race 23. The upper end of guide lug 10 is still at this time engaged within the vertical slot of sleeve 9. This assures the engagement of race followers 24 with race 23 before the lug 10 becomes disengaged from guide sleeve 9. The body V25 may be moved vertically below the tubing 18 with the race 23 and followers 24 preventing angular movement of the body 25. The guide llug 10 and race followers may be positioned adjacent the lower end or upper end of body 25. n

The spring biased means 24 are carried angularly by the body 25 to describe or enclose an angle no greater than 90 such that on release of the spring biased means 24 from the recesses 28 formed in the body 25, they spring out into engagement with the race 23. On contact of the spring biased means 24 with the race 23. an electrical circuit is completed through the body member 25 and the conductor cable 27 to actuate the perforating means 26 and to cause perforation of thecasing 11 to form the perforations 29. As shown in FIGS. l and 2, a plurality of horizontally and vertically spacedapart perforatingmeans 26 are arranged in body member 25 -to iire in 'a plurality of directions to perforate the casing 11. By having a circuit completed through 3 the race 23 and the spring biased means 24, there is no danger of the tubing 14 being perforated and only the casing 111 is perforated.

Referring now to FIG. 4, it will be noted that the casing 11 has arranged therein a tubing string 30,'which has attached adjacent to its lower end 31 an offset tail pipe 32 which communicates fluidly with the tubing 30 by passageway 33. Depending from the tubing 30 and attached longitudinally or carried longitudinally to the tail pipe 32 by attaching means 34 is a race 35 which is similarto the race v23 of FIG. 1. Tubing 30 is also provided witha guide sleeve 9 as in FIG. 1. A perforator including abody member and perforating means 26 such as sho-wnrin FIGS. l, 3, and 4 may suitably be lowered out of the tubing 30 and positioned on the race 35 to perforate the casing 11 as has been described'with respect to the other" gures of thedrawing.

If it is' desired to employ the tail pipe 32 for per' ,l marient well completion operations such as sand washing'or removing excess uid cement', the lower open en'd 31 of the tubing 30 may be closed by lowering a plug 36 provided with a sealing means 37 ona wire line such as 27 such that the passageway for iiuid may be through tube 30 and tail pipe 32 and -up the casing-tubing annulus 38 or i-n a reverse direction.

While the invention has been described and illustrated particularly with respect to single and/or dual completions, the invention is equally applicable to other multiple completions such as triple or quadruple or even a greater number of completions where three or even four or more tubing strings may be arranged in a well bore or casing with each tubing string having its lower end terminating above' a hydrocarbon productive interval to be perforated and through which the other tubing strings extend.

The present invention is quite advantageous and useful in that means are provided by way of which a gun perforator may be used to perforate a casingv containing eccentrically arranged pipes where one pipe extends through a zone where its is desired to form perforations without perforating that pipe extending through that zone.

The nature and objects of the present invention having been completely described and illustrated, what I wishto` claim as new and useful and secure by Letters Patent is:

1. Perforating apparatus comprising a casing having at least first and second parallel eccentrically arranged pipes therein with va first of said pipes extending through a zone to beperforated, a guide sleeve carried in theV lower end of said second pipe, an elongated body adapted to be'lowered into said zone through the second of said pipes Ito a position adjacent a first of said pipes, a pluality of horizontally and vertically spaced-apart perforating means arranged in said body and directed in a shoulders for maintaining said race follower means in cooperative engagement, and elongated rigid means engageable with said guide sleeve arranged and extending on said body longitudinally above and below said race follower means and opposite the angle described by said race follower means for orienting and maintaining said body and perforating means in an oriented position in a direction facingsaid casing and away from said first pipe as it is lowered out of said second pipe, said elongated means and said race follower means, respectively, sequentially engaging said guide sleeve and said race, and said springbiased race follower means and said race cooperatively engaging to maintain said body in said `oriented position as it is lowered into said zone. y

2. Perforating apparatus comprising a casing having at least rstrand second parallel eccentrically arranged pipes thereinv with a rst of said pipes extending through a zone to be perforated,v a guide sleeve carried in the lower' end of said second pipe, an elongated body adapted tobe lowered into said zone through the second of said pipes to apposition adjacent a iirst of said pipes, a plurality of horizontally yand vertically spaced-apart perforating means arranged in said body and directed in a predetermined position for perforating said casing, a race having its upper end dependingly connected to the lower end of saidl second pipe, said race being carried longitudinally by said iirst pipe aund having an operative curved surface facing away from saidr first pipe toward said casing, two spring-biasedV race follower means carried in' recesses by said body, said race follower means describing an angle no greater than when extended from said recesses and being carried by said body memberv to position said perforating means away from said rst pipe such that on operating said perforating means only -said casinglis perforated, said race being provided with inwardly directed' shoulders for maintaining said race follower means in cooperative engagement, andv elongated rigid guide lug means engageable with said guide sleeve arranged and extending on said body longitudinally above and below said race follower means and opposite the angle described by said race follower means for maintaining said body and perforating means in an oriented position in a direction facing said casing and away from said first pipe as it is lowered out of said second pipe, said elongated guide lug means and said race follower means, respectively, sequentially engaging saidv guide sleeve and said race, and said spring-biased race follower means and said race cooperatively engaging to maintain said body in said oriented position as it is lowered into said` zone, and vmeans connected to said perforating means and -to said race follower means and said race such that said perforating means is operable only when said race follower means and said race operatively engage.

References Cited in the le of this patent UNITED STATES PATENTS 2,679,899 Osborn June 1, 1954 2,785,754 True Mar. 19, 1957 2,796,023 Abendroth June 18, 1957 2,891,620 Bielstein June 23, 1959 

